1. Field of the Invention
The present invention relates to a transmission line switching apparatus and a transmission line switching method which can be applied to a switching apparatus of a communication network using optical fibers.
2. Related Background Art
As shown in FIG. 1, a conventional optical fiber switching apparatus includes an optical fiber connecting board 5 for connecting a plurality of first optical fibers 2 of a first optical fiber cable 1, such as an office optical fiber cable, to a plurality of second optical fibers 4 of a second optical fiber cable 3, such as a subscriber optical fiber cable.
A plurality of through holes are formed in a matrix form in the optical fiber connecting board 5, and a connector adapter 6 is fitted in each through hole. A connector plug (not shown) is attached to the end portion of each first optical fiber 2. This connector plug is inserted from one side into the connector adapter 6 and fixed in it. A connector plug 7 is also attached to the end portion of each second optical fiber 4. This connector plug 7 is detachably inserted from the other side into the connector adapter 6. Therefore, it is possible to switch the connections between the first and second optical fibers 2 and 4 by changing the connector adapters 6 into which the connector plug 7 of the second optical fiber 4 is to be inserted.
When the second optical fibers 4 of the second optical fiber cable 3 are inserted directly into the connector adapters 6 of the optical fiber connecting board 5, these second optical fibers 4 are entangled. To reduce this entangled state, therefore, an optical fiber arranging board 8 is disposed horizontally at a position above and in front of the optical fiber connecting board 5. In this optical fiber arranging board 8, through holes are formed in a matrix form so that the second optical fibers 4 are passed through these holes. The second optical fibers 4 are held in a two-dimensionally arranged state after being passed through these through holes. When the connector plugs 7 of the second optical fibers 4 are connected to the optical fiber connecting board 5, the second optical fibers 4 suspended from the optical fiber arranging board 8 are loosened, as illustrated.
Generally, such a switching apparatus is manually handled by a worker. That is, a worker selects one of the second optical fibers 4, as an object to be switched, holds the connector plug 7 of the selected fiber 4 between his or her fingers, and removes the selected fiber 4 from the connector adapter 6 of the optical fiber connecting board 5. Thereafter, the worker inserts the removed connector plug 7 into another connector adapter 6.
In the above-mentioned switching apparatus, the second optical fibers 4 are entangled in front of the optical fiber connecting board 5. Therefore, it is difficult to chose a desired one from these second optical fibers 4.
In addition, the bundle of the second optical fibers 4 in front of the optical fiber connecting board 5 interferes with a rapid operation in inserting the connector plug 7 into the connector adapter 6. Also, there is the possibility that the second optical fibers 4 cross complicatedly one another to worsen the entangled state, as the switching operation proceeds.
Furthermore, in the manual operation performed by a worker, the worker may damage the second optical fibers 4 other than a desired fiber or connect the desired fiber to a wrong position by mistake.